- Utilization of Donor–Acceptor Interactions for the Catalytic Acceleration of Nucleophilic Additions to Aromatic Carbonyl Compounds
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A conceptually new method for the catalytic electrophilic activation of aromatic carbonyl substrates, by utilizing donor–acceptor interactions between an electron-deficient macrocyclic boronic ester host ([2+2]BTH-F) and an aromatic carbonyl guest substrate, was realized. In the presence of a catalytic amount of [2+2]BTH-F, dramatic acceleration of the nucleophilic addition of a ketene silyl acetal towards either electron-rich aromatic aldehydes or ketones was achieved. Several control experiments confirmed that inclusion of the aromatic substrates within [2+2]BTH-F, through efficient donor–acceptor interactions, is essential for the acceleration of the reaction.
- Uchikura, Tatsuhiro,Ono, Kosuke,Takahashi, Kohei,Iwasawa, Nobuharu
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supporting information
p. 2130 - 2133
(2018/02/06)
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- PARTIALLY FLUORINATED HETEROCYCLIC COMPOUNDS PART 28. THE HYDROLYSIS OF 1,3,4,5,6,7,8-HEPTAFLUORO-2-NAPHTHYLIDENERHODANINE TO FORM RING-FUSED THIOPHENES. A SIGNIFICANT PROPORTION OF A LINEAR NAPHTHOTHIOPHENE DERIVATIVE ACCOMPANYING AN ANGULAR NAPHTHOTHIOPHENE DERIVATIVE
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1,3,4,5,6,7,8-Heptafluoronaphthalene-2-carbaldehyde (7), prepared via a Grignard reaction from 2-bromo-1,3,4,5,6,7,8-heptafluoronaphthalene (9) with N-methylformanilide, reacted with rhodanine to give 1,3,4,5,6,7,8-heptafluoro-2-naphthylidenerhodanine (5).Hydrolysis of (5) with base gave a mixture of 4,5,6,7,8,9-hexafluoronaphthopthiophene-2-carboxylic acid (11) and 4,5,6,7,8,9-hexafluoronaphthothiophene-2-carboxylic acid (12) resulting from the intermediate thiolate (6) displacing fluorine at sites 3 and 1 in the naphthalene ring in the ratio 22:78 respectively, which represents a significantly high portion of the linearly cyclised product accompanying the angularly cyclised product.Decarboxylation of the mixture of (11) and (12) gave 4,5,6,7,8,9-hexafluoronaphthothiophene (13) and 4,5,6,7,8,9-hexafluoronaphthothiophene (14) respectively, while treatment of the mixture (11) and (12) with diazomethane gave an inseparable mixture of the methyl 2-carboxylates (15) and (16) respectively.
- Brooke, Gerald M.,Meara, Jeremy M.
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p. 229 - 242
(2007/10/02)
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- Partially Fluorinated Heterocyclic Copmpounds. Part 27. The Synthesis of 4,5,6,7-Tetrafluorobenzothiophene and 4,5,6,7,8,9-Hexafluoronaphthothiophene; some Chemistry and Electrochemistry
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2,3,4,5,6-Pentafluorobenzyl methyl sulphoxide (6) is readily converted by butyl-lithium into 4,5,6,7-tetrafluorobenzothiophene (8) and 1,3,4,5,6,7,8-heptafluoro-2-naphthylmethyl methyl sulphoxide (9) in a similar manner gives a very low yield of 4,5,6,7,8,9-hexafluoronaphthothiophene (11) accompanied by the 7- and 8-butylated derivatives (12) and (13) respectively, and also 1,3,4,5,6,7,8-heptafluoronaphthalene-2-carbaldehyde (10).Compound (8) undergoes Diels-Alder addition reactions followed by sulphur elimination with dimethyl acetylenedicarboxylate and tetrafluorbenzyne to give the naphthalene and anthracene derivatives (14) and (15) respectively.With lithium propane-2-thiolate, compound (8) gives the 5-propan-2-ylthio and 5,6-bispropan-2-ylthio derivatives (16) and (17) respectively.Compound (8) is polymerised by SbF5-HF to poly(1,3-dihydro-4,5,6,7-tetrafluorobenzo-thiophene) (20).The electrochemical anodic oxidation of (8) has been studied extensively: polymer (20) is produced accompanied by a deep red material readily soluble in chloroform, which is not poly(4,5,6,7-tetrafluorobenzothiophene) (24).
- Brooke, Gerald M.,Mawson, Simon D.
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p. 1919 - 1923
(2007/10/02)
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